bug#65772: kmail fails to start "unable to obtain agent type"

[nik gaffney via Bug reports for GNU Guix]

It appears that kmail requires akonadi to provide a few extra Agent Types.
as of kmail 23.04.3 the following are listed as dependencies

 * akonadi
 * akonadi-contacts
 * akonadi-mime
 * akonadi-search

installing the following packages enables kmail to start up. The import 
& account wizards are still unavailable so you may need to add any 
account settings manually.

 * akonadi
 * akonadi-calendar
 * akonadi-contacts
 * akonadi-mime
 * akonadi-notes
 * akonadi-search